Line cutout clamp



Jan. 25, 1955 s-n so 2,700,712

LINE CUTOUT CLAMP Filed July 1, 1953 LEUNARD E. ST/NSO/V INVENTOR.

ATTORNEYS United States Patent LINE CUTOUT CLAMP Leonard E. Stinson, Wakefield, Mass.

Application July 1, 1953, Serial No. 365,326

12 Claims. (Cl. ZOO-115.5)

This invention relates to line connectors for use in emergency repair of electric lines in a live circuit.

Heretofore, the usual type of line connector has included a pair of threaded clamps joined by a short length of rubber insulated wire, the clamps also being covered, so far as practical, with thick rubber insulation.

When an electric line, extending between poles, has

broken, the repairman has usually climbed the pole nearest the break and installed a Well known type of connecting automatic line splice on an end of the broken section of the line. The automatic line splice is arranged to grip and hold at each opposite end thereof a wire inserted therein and it is the insertion of the end of the other section of the broken line that is the difiicult and dangerous portion of the repair. Since the live circuit may carry from 2,300 volts up to 10,000 volts that can be safely handled, a line connector has been threadedly clamped on each opposite side of the break to bypass all of the current and permit the repairman to insert the end of the broken section in the automatic line splice without being injured or killed. After such insertion, the automatic line splice retains both broken ends of the line and the line connector is removed.

' Usually such breaks occur during a rain storm, often at night, and the threaded clamps of the line connectors now in use tend to create arcs when being clamped in place, much to the discomfort and danger of the repairman. The repairman may also becorne even more nervous, and his work more inaccurate and inefiicient, by reason of his knowledge that he holds a line connector in his insulated gloves which is about to complete a high voltage circuit which may arc in his face and which he must nevertheless tighten into place by a slow operating fine threaded knob.

The principal object of this invention is to provide a line connector, easily handled by a repairman, and having at least one of its clamps provided with means for opening the circuit therethrough during its installation to reconnect a live circuit.

Another object of the invention is to provide a line connector which can also be provided with a fusible element for temporary installations requiring a fuse.

Still another object of the invention is to provide in a line connector at least one clamp having a quick acting coarse threaded connection capable of being tightened on a line in about 6 /2 turns or less.

A further object of the invention is to provide a novel clamp housing for a line connector clamp which incorporates both a pivoted contact arm and a threaded clamp and can be easily handled by a repairman in a precarious perch under storm conditions.

Still another object of the invention is to provide a line connector of simple durable construction which closes a live circuit after being clamped in place rather than as soon as it touches the live circuit thereby avoiding arcing and danger to the repairman.

In the drawing, Fig. 1 is a perspective view of the line connector of this invention in use.

Fig. 2 is a side view, partly in section, of a line connector clamp constructed in accordance with the invention.

Fig. 3 is a front view of the clamp shown in Fig. 2, and

Fig. 4 is an end view of the clamp shown in Fig. 2, in section on line 44 of Fig. 2 and with the circuit therethrough closed.

In Fig. 1, a typical line connector installation is 2,700,712 Patented Jan. 25, 1955 illustrated such as may occur when one of the two main electric lines 20 and 21 breaks due to a storm or otherwise. Lines 20 and 21 are tied in on insulators 22 and 23 on the cross arm 24 of a pole 25. As indicated in dotted lines, one broken section 26 of line 21, may hang down from insulator 22 and the other broken section 27 of line 21 usually rests on the ground, or hangs in the trees, creating a dangerous hazard. An automatic line splice S, of a well known type is usually slipped over the end of the broken section 26 and it then becomes the task of the repairman to insert the end 30 of the other broken section 27 in the opposite end of the automatic line splice S to repair the line.

At present, line connectors are used which include a pair of identical clamps such as C of a well known type, joined by a connector line similar to line B, to by-pass all of the 2,300 to 10,000 volts in line 21. One clamp C is attached to the broken section 27 of line 21 and the other clamp C is attached in rear of the end 31 of the other broken section 26 of line 21. Usually an arc occurs as soon as the second clamp C is engaged around the line 21, since the circuit is then completed, and the arcing usually continues while the lineman seeks to threadedly tighten the fine threads of the clamp to make a connection that will not vibrate loose.

The line connector M of this invention comprises a connector clamp C, a connector wire or line B, and a cutout clamp A and arcing is thereby avoided. A preferred embodiment of cutout clamp A is shown in Figs. 2, 3 and 4 and includes an elongated housing 40 having a housing cover 41 pivoted thereto at 43. An electric conductor 44 extends longitudinally within housing 40 and is provided with a break at 45, intermediate thereof, which break may be of various lengths, but is preferably about 2. /8 to 2% inches in length.

One terminal end 46 of conductor 44 includes a recess 47 for the end of the connector line B which is held therein by set screws such as 48 and 49. The other terminal end 50, of conductor 44 forms a stationary clamping jaw 51 and preferably also extends around a movable clamping jaw 52 as at 53, 54, 55 and 56.

Movable jaw 52 is mounted to slide within the portions 53, 55 and 56 of conductor 44 and is provided with a post 58 having coarse exterior threads 59, which is /213 right hand thread, engaged in the course interior threads 60 of a sleeve-like member 61 which has a %10 left hand exterior thread, screwed into 54. The member 61 is attached to a knurled knob 62. The clamping mechanism is so arranged that by turning knob 62 about 6%. turns the movable jaw 52 is caused to move from its open position to its closed position to firmly grasp a main live electric line such as 21 between jaws 52 and 51. Jaw 52 is preferably curved at 64 to form a recess for receiving line 21 and jaw 51 is preferably curved at 65 to receive the curved portion 64.

In view of the break 45 in conductor 44, it will be apparent that no circuit is completed between connector line B and main line 21 when jaw 52 has been tightened against jaw 51 and that therefore no arcing can take place. Means for closing the break 45 in conductor 44 are pro-. vided which in the embodiment shown comprises an electric conducting contact arm attached to the inside of housing cover 41. Preferably two pairs of resilient fingers 70 and 71 are provided, one on each opposite side of break.

45 and each attached to conductor 44 by screws such as 72 and 73. Each pair of fingers such as '70 and 71 is adapted to receive the squared portion 92 and 93 of a slidable tube 74 of the solid or fusible type well known in the art. The tube 74 is slidably mounted in fuse holders 75 and 76 fixed to the inside 77 of housing cover 41. Thus when cover 41 is opened it carries with it tube 74 thereby breaking the circuit between fingers 70, 71. Line connector M is installed with cover 41 open to avoid any possibility of arcing. After line 21 has been firmly engaged in jaws 52 and 51, cover 41 is closed which positions tube 74 in fingers 70 and 71 and completes the circuit across break 45 and through line connector M.

It should be noted that cutout clamp A is of a cross sectional area which permits it to be grasped in one hand of a repairman, it being generally rectangular in cross section with its narrower sides 82, 83 about three inches 3 or les's in =width and its'wider sides 80 and 81 about five inches in width. Preferably, also, the exterior of the clamp A is corrugated as at 85 to facilitate grasping the same, and the major portion of the exposed surface of both housing 40 and cover 41 is covered with a thick layer of electrical insulation 86.

A looped element, or handle90, is provided on cover 41 whereby the cover can be opened and closed by the fingers or 'by ahooked po'le well known in the art. The loop 90 is preferably positioned proximate the knurled knob 62 in position to interfere somewhat with rotating the knob 62 by hand. The presence of loop 90 thus serves as 'a Warning to the repairman that the cover 41 is closed and the circuit complete through line connector M, thus'indicating the desirability of opening the circuit before seeking to turn knob '62.

Inop'eration, the clamp A with cover 41 open is tightened on broken section 26, then clamp Cris tightened on broken section 27. Cover 41 is then closed to 'by-pass the 'live current in main line '21,' without arcing, whereupon the end 30 and 31 of broken section 26 and 27 is inserted in the automatic line splice S to complete the repair. Clamps A and C 'are'then removed 'for other use. If it is desired to protect a transformer with a fuse after its cutout has been destroyed, it is only necessary to slidablysubstitute a fusible tube for the solid fuse 74 in fuse holders 75 and 76, whereupon the fusible tube will break the circuit at a predetermined voltage in a well known manner, thus protecting the transformer until permanent repairs can be made.

I claim:

1. A portable line connector for connecting one broken section or" a live electric main line with theother broken section thereof, said line connector comprising the combination of a first connector clamp of insulated conductor material for removably engaging one broken section of said live electric line; a second connector clamp of insulated conductor material for removably engaging the other broken section of said live electric line; a connector line of insulated conductor material joining said clamps and completing an electric circuit therethrough from one broken section of said main line to the other broken section thereof and manually operable switch means including a contact arm pivotally mounted on one of said connector clamps for opening the circuit through said line connector during installation on said mainline.

2. A combination as specified in claim 1 wherein the connector clamp having said pivoted contact arm is provided with coarse threaded clamping mechanism for quickly attaching the same to a section of said live electric main line.

3. A combination as specified in claim 1 wherein the connector clamp having said switch means includes a fuse tube as its pivoted contact arm for opening the circuit therethrough at a predetermined voltage.

4. A combination as specified in claim 1 wherein said switch means includes a cover pivoted to said clamp and said contact arm is a fuse removably retained in fuse holders on said cover to complete the circuit through said clamp when said arm is in closed position.

5. A combination as specified in claim 1 wherein the connector clamp having said switch means is provided with a turning knob for threadedly attaching the clamp to a main line and the pivoted arm is provided with an upstanding loop for closing the same, said loop being proximate said knob to interfere with manually turning the knob when the cover is in closed position.

6. A line connector clamp for use in attaching a 'connector line to a live electric main line, said clamp comprising an elongated housing of a cross sectional area small enough to be grasped by hand; an electric conductor extending longitudinally within said housing and having a break intermediate thereof, one terminal end of said conductor being arranged to receive, conductively connect with, and hold an end of said connector line and the opposite terminal end of said conductor forming a conductive stationary clamping jaw; a movable clamping jaw conductively connected to said stationary jaw and carried by said housing opposite said stationary clamping jaw; manually operable means for moving said movable jaw toward said stationary jaw 'to grasp said main electric line therebetween and conductively connect therewith and electric conducting means pivotally mounted on said housing for closing the break in said conductor to complete a circuit from said connector line, through said clamp conductor, said means and said jaws, to the main line grasped in said jaws.

7. A line connector clamp as specified in claim 6 wherein said manually operable means includes a turning knob and a coarse fast traveling right and left hand threaded connection between said turning knob and movable jaw.

8. A line connector clamp as specified in claim 6 wherein said electric conducting means includes a solid fuse removably mounted on the inside ofa-housing cover of insulating material and includes a housing cove-r pivoted to said housing.

9. A line connector clamp as specified in claim 6 wherein said manually operable means includes a knob for threadedly advancing said movable jaw and said electric-conducting means includes a pivoted cover on said housing, said cover having a looped handle element in position to interfere with the manual turning of said knob when the cover is in closed position. 7

10. A line connector clamp as specified 'inclaim 6 .plus a pair of resilient fingers of electric conducting material, one on each side of the break in said electric conductor, for receiving said pivotally mounted electric conducting means and conductively connecting the same across the break in said conductor.

11. A line connector clamp for use in attaching a connector line to a live electric main line, said clamp comprising an elongated insulated housing of a cross sectional area small enough to be grasped by hand; an electric conductor extending longitudinally within said housing and having a break intermediate thereof; a course threaded clamp on said housing at one terminal end of said conductor for grasping said live electric main line and conductively connecting the same with the adjacent end of said conductor; a connector line fixed to the other terminal end of said electric conductor within said housing and conductively connecting the same with said connector line; a cover extending longitudinally of, and pivoted, to said housing and a conductive member, removably mounted along the inside of said cover coextensively with the break in said conductor for closing the break in said conductor to complete a circuit thereacross when said cover is closed.

12. A clamp as specified in claim 11 wherein said conductive member is a sliding tube fuse mounted in spaced-apart, resilient fuse holders on said cover, and said electric conductor includes a pair of resilient fingers oneach side of said break each pair of fingers adapted to receive one of the opposite ends of said fuse and conductively connect the fuse across the break in the conductor.

References Cited in the file of this patent UNITED STATES PATENTS 

